src/machine/operation.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2016 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include "alloc-util.h"
  21 #include "fd-util.h"
  22 #include "operation.h"
  23 #include "process-util.h"
  24
  25 static int operation_done(sd_event_source *s, const siginfo_t *si, void *userdata) {
  26         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
  27         Operation *o = userdata;
  28         int r;
  29
  30         assert(o);
  31         assert(si);
  32
  33         log_debug("Operating " PID_FMT " is now complete with with code=%s status=%i",
  34                   o->pid,
  35                   sigchld_code_to_string(si->si_code), si->si_status);
  36
  37         o->pid = 0;
  38
  39         if (si->si_code != CLD_EXITED) {
  40                 r = sd_bus_error_setf(&error, SD_BUS_ERROR_FAILED, "Child died abnormally.");
  41                 goto fail;
  42         }
  43
  44         if (si->si_status != EXIT_SUCCESS) {
  45                 if (read(o->errno_fd, &r, sizeof(r)) == sizeof(r))
  46                         r = sd_bus_error_set_errnof(&error, r, "%m");
  47                 else
  48                         r = sd_bus_error_setf(&error, SD_BUS_ERROR_FAILED, "Child failed.");
  49
  50                 goto fail;
  51         }
  52
  53         r = sd_bus_reply_method_return(o->message, NULL);
  54         if (r < 0)
  55                 log_error_errno(r, "Failed to reply to message: %m");
  56
  57         operation_free(o);
  58         return 0;
  59
  60 fail:
  61         r = sd_bus_reply_method_error(o->message, &error);
  62         if (r < 0)
  63                 log_error_errno(r, "Failed to reply to message: %m");
  64
  65         operation_free(o);
  66         return 0;
  67 }
  68
  69 int operation_new(Manager *manager, Machine *machine, pid_t child, sd_bus_message *message, int errno_fd) {
  70         Operation *o;
  71         int r;
  72
  73         assert(manager);
  74         assert(child > 1);
  75         assert(message);
  76         assert(errno_fd >= 0);
  77
  78         o = new0(Operation, 1);
  79         if (!o)
  80                 return -ENOMEM;
  81
  82         r = sd_event_add_child(manager->event, &o->event_source, child, WEXITED, operation_done, o);
  83         if (r < 0) {
  84                 free(o);
  85                 return r;
  86         }
  87
  88         o->pid = child;
  89         o->message = sd_bus_message_ref(message);
  90         o->errno_fd = errno_fd;
  91
  92         LIST_PREPEND(operations, manager->operations, o);
  93         manager->n_operations++;
  94         o->manager = manager;
  95
  96         if (machine) {
  97                 LIST_PREPEND(operations_by_machine, machine->operations, o);
  98                 o->machine = machine;
  99         }
 100
 101         log_debug("Started new operation " PID_FMT ".", child);
 102
 103         /* At this point we took ownership of both the child and the errno file descriptor! */
 104
 105         return 0;
 106 }
 107
 108 Operation *operation_free(Operation *o) {
 109         if (!o)
 110                 return NULL;
 111
 112         sd_event_source_unref(o->event_source);
 113
 114         safe_close(o->errno_fd);
 115
 116         if (o->pid > 1)
 117                 (void) sigkill_wait(o->pid);
 118
 119         sd_bus_message_unref(o->message);
 120
 121         if (o->manager) {
 122                 LIST_REMOVE(operations, o->manager->operations, o);
 123                 o->manager->n_operations--;
 124         }
 125
 126         if (o->machine)
 127                 LIST_REMOVE(operations_by_machine, o->machine->operations, o);
 128
 129         free(o);
 130         return NULL;
 131 }